Environmental Rules in Alameda County, CA (2026)

4 county-level rules, plus city-specific rules for 6 cities in Alameda County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Alameda County. If you live within an incorporated city, that city's own rules apply — see the city list below.

Stormwater Management

Alameda County complies with SF Bay Regional Water Board MRP 3.0. Projects disturbing 10,000 sf or more must incorporate Low Impact Development treatment per Provision C.3.

Stormwater Rules in Alameda County

Heavy Restrictions

Full ordinance details →Official source ↗

Erosion Control

Alameda County requires erosion control during the rainy season (October 1 to April 30). Projects over 1 acre need a Construction General Permit and a SWPPP.

Erosion Control in Alameda County

Heavy Restrictions

Full ordinance details →Official source ↗

Flood Zones

Alameda County participates in NFIP. FEMA maps designate Special Flood Hazard Areas along the Bay shoreline in Oakland, Alameda, San Leandro, Hayward, and creek corridors countywide.

Flood Zones in Alameda County

Heavy Restrictions

Full ordinance details →Official source ↗

Grading & Drainage

Alameda County regulates grading under Title 15 and CBC Appendix J. Permits are required for cuts or fills over 50 cubic yards or 3 feet in depth; hillside overlays have stricter rules.